Velocity-reducing and filtering inlet for hydraulic tanks



G. w. MORK Feb. 16, 1954 VELOCITY-REDUCING AND FILTERING INLET FOR HYDRAULIC TANKS Filed April 21, 1948 QEo aE w. MORK,

INVENTOR,

' BY w ATTORNE Y Patented Feb. 16,, 1954 VELOCITY-REDUCING AND FILTERING INLET FOR HYDRAULIC TANKS George W. Mork, South Milwaukee, Wis., assignor to Bucyrus-Erie Company, South Milwaukee, Wis., a corporation of Delaware Application April 21, 1948, Serial No. 22,445

8 Claims.

' tractor equipment more particularly to means for retarding, uniformly distributing, and purifying the liquid in suchunits to increase operating efficiency.

Such hydraulic units comprise an hydraulic storage tank or tanks, an hydraulic pump, the control valve for controlling the flow to and from the pump, means for actuating the valve, and various incidental conduits, relief valves, and one-way valves. An hydraulic unit of the general sort to which my invention is applicable is described in the 'copending application of myself and Gottfried Renter, Serial No. 642,924, filed January 23, 1946, now Patent No. 2,581,340 of January 8, 19 52, for Hydraulic Unit, to which application reference is made.

In such hydraulic units, when the circulating liquid is returned to the tank and mixes with the liquid already in the tank, it sets up a turbulence which aerates the liquid. Such aeration is harmful since it causes jerky operation of the cylinder-piston assemblies that actuate the tractor equipment, causes knocking in the conduits, and increases the volume of the liquid which then overflows.

Accordingly the principal object of my invention is to provide a simple, compact, and automatically-functioning means for eliminating such objectionable turbulence in the hydraulic unit.

A further object of my invention is to provide means for effecting uniform distribution of the liquid as it enters the hydraulic unit.

A further object of my invention is to provide means for cleaning the liquid as it passes into the tank.

In addition to the objects above stated, I have worked out a number of novel and useful details, which will be readily evident as the description progresses.

My invention consists in the novel parts, and in the combination and arrangement thereof, which are defined in the appended claims, and of which one embodiment is exemplified in the accompanying drawings, which are hereinafter particularly described and explained.

Throughout the description, the same reference number is applied to the same member or to similar members.

Referring now to the accompanying drawings, it will be seen that:

Figure l is a general vertical front elevation of the hydraulic unit to which my invention is applied, the tanks and flow retarder therein being shown cut away in section.

Figure 2. is a plan view of my flow retarder, taken along the lines 2-2 of Figures 1 and 3.

Figure 3 is an enlarged vertical section of my flow retarder, taken along the line 3-3 of Figure 2. r

Referring now to Figure 1, we see that the hydraulic unit comprises two tanks H attachedto the sides of main housing 12 which contains most of the conduits and supports the auxiliary pump housing 53, and a control-valve casing l4 resting on top of the main housing. The pump is driven directly by the front power-take -off shaft of the tractor (not shown). 1

Liquid is normally returned from the valve to each tank through a passage l5 which is located along the side of main housing I2 and leads to opening it in tank bottom I! which is normally completely closed except at opening l6.

Located within the tank are one or more horisontally spaced cylindrical baffles which are preferably vertical and coaxial withopening l6, Each baflie consists of either a lower baflie l8 mounted on and extending upwardly from the preferably edge of each upper baffle I9 is spaced above tank bottom ll, so that the liquid passes outwardly successively upwardly and downwardly through the series of compartments '220r-b-C formed by the overlapping portions of the successive lower and upper bafiies. The baffles are of progressive- 1y increasing diameter, -5 that the compartments have preferably a constant height, but progressively increasing horizontal cross-section proportional to the square of their radius. As the liquid flows outwardly from one compartment to the next, two effects occur: (1) velocity of the liquid decreases in inverse proportion as the cross section of the compartments increases; and (2) pressure within each compartment is equalized insuring uniform distribution of flow around the periphery of the velocity retarder inlet. This last-mentioned pressure equalization is effected by the baflles which set up a slight back pressure (due to friction and deflection) which equalizes any difference in pressure and resulting non-uniform flow around the inlet due to bafile plate 28 not being exactly parallel to tank bottom #1, or to non-uniform flow at inlet 6.

Thus we see that baffle plate 20 and tank bottom I! form in eifect a Venturi orifice in which there is the velocity retardation normally characteristic of such an orifice, plus pressure equalization resulting in uniform flow distribution around the outer periphery of the orifice. the latter being accomplished by a series of intermeshing corrugations (or baflies) on the inner sides of the orifice. In the particular preferred embodiment shown 'in Figures. 1'-3, the sides of the orifice are in effect two vertically spaced horizontal circular plates, the progressive retardation of velocity being secured by having the liquid move radially outwardly between'the .platesfrom their center to their periphery and past a series of intermeshing concentrically circular corruga-. tions located between theplates. i In. this way turbulence of the liquid emitted by theinletis eliminated and uniform fiow distribution effected by a very compact structurein a'space that could not possibly accommodatea conventional trumpet-shaped Venturi orifice.

I prefer to show baffles l8 and I9 in the .form

-orvertica1 concentric" cylinders; instead of "outwarril'y flaring frust'o-cones; because, although *"theilatter arrangement-would secure more uniform Venturir'etardation, my preferred arrangement is simpler to manufacture, especially when the upper and lower walls andtheirrespective i'plates-are cast "in one-piece. 'Howevenit is obvi- "ousthat such a"preferred'embodiment shown in "'the drawings is" not essential, and that my 'in yentlon may be embodied in various other forms.

'-Turning now-to-the'second'feature of my in- --vention, we see that it is possibleto utilizemy flow retarder also to filter the liquid conven- "iiently by"modifying"my inlet in two'respects. ----First; I make the outermost upper'bafiie in the foimof a screen. Secondly,I add a troughshaped screening element 23 around the lower edge of that baifie andextendinginwardly across the lower part of the outermost compartmen't 220.

"of-"h m invention, '1' wish it to be understood that mylnvention'is not to be limited to the specific "f-o'r'm 'or arrangement of parts herein described substantially parallel plates; an upstreamopenthe upstream opening;l"said downstream opening being located in the plate-and-baffle assembly adjacent the periphery of the outermost annular baflie; the cross-sectional area of the downstream opening being materially greater than that of i theupstream opening; said velocity-reducing hydraulic-fiuid inlet being further characterized by -thefactlthat onelof said annular baffles is spaced fromlthe-opposite plate and from any adjacent bafiie so as to leave a space for the passage of "-liquid-therebetween, and by having perforated basket. means that is connected to said one of the baffles adjacent the free edge of such bafile and that extends only partly across said ,space,

.yrsaidb'asket .meansithereby"catching and. holding particles filtered out of the liquid, .as' theliquid passes through said space.

'2. A velocity-"reducing hydraulicefluid. inlet,

according to "claim' 1, furthercharacterized by the fact that said one of. the baflies is .the' outer- "most' baflie; and that the basket means'is hookshaped in cross-section and points inwardlyupstream.

' 3. A velocity-reducing hydraulic fiui'd' inlet,

according to claim 2, further :characterizedby the fact'thatsaid'outermost bafflaitself: consists at least inpart "of a' filteriscreen.

GEORGE "MORK.

References Cited in" the file 0f this 'patent UNITED;v STATES. PATENTS 'rNllmbi-ll Name Date 3.4 21962 s-Hill Y*June 1,1886 896,479 Sussmann Aug. "18, 1908 $973,057 Mader .4 Oct. 18, 1910 1,087,242 'u-Kelly Feb. 17,1914 1,169,792 'French Feb. 1,":1916 1,527A29 #Ericson Feb.'24, 1925 1,726,328 Wieand Aug.'127,'.19.29 1,821,619 ;I.-Day.. l "'I-Sept; 11,1931 :..1,-897,572 Cornell Feb. 14,1933 $2,435,359 '-Landis.. -lFeb. 3, 1948 FOREIGN PATENTS Number Country Date 26,779 Gnreat liiritain 1912 "71,373 Switzerland "1916 414,288 vGermany 1925 

